Rectal cancer, which accounts for approximately 40% of colorectal cancers, remains a major clinical concern. Recent advances in diagnostic imaging, surgical techniques, radiotherapy, and systemic treatment have steadily improved rectal cancer outcomes. Considering this, the Korean Rectal Cancer Multidisciplinary (KRCM) Committee has aimed to provide clinicians and policymakers with up-to-date, evidence-based clinical practice guidelines to support optimal decision-making, reflecting current evidence, the Korean healthcare context, and patient values and preferences. The Clinical Practice Guidelines for Rectal Cancer version 2.0 were developed through multidisciplinary collaboration with related academic societies, building upon and updating the KRCM Clinical Practice Guidelines version 1.0 (titled “Multidisciplinary guidelines for the management of rectal cancer”). These consensus guidelines of the KRCM were established based on a comprehensive literature review, evidence synthesis, with recommendation development guided by the GRADE (Grading of Recommendations Assessment, Development and Evaluation) methodology, and consideration of applicability in real-world clinical practice under the national health insurance system. Each recommendation has been presented with its strength and level of evidence.

Background: s/Aims: Pancreaticoduodenectomy (PD) is the standard treatment for periampullary tumors, but it is technically challenging. Evidence directly comparing open, laparoscopic, robotic, and hybrid approaches is limited. This study conducts a network meta-analysis (NMA) to compare the perioperative and oncologic outcomes of open PD (OPD), laparoscopic PD (LPD), robotic PD (RPD), and hybrid PD. Methods: We searched PubMed, EMBASE, and the Cochrane Library for studies published between January 1994 and August 2024.We included randomized controlled trials and comparative observational studies that evaluated at least two PD approaches. Perioperative outcomes were the primary endpoints, while oncologic safety served as a secondary endpoint. A random-effects NMA was performed, establishing treatment hierarchies through ranking probabilities (PROSPERO ID: CRD420250365864). Results: A total of 78 studies were included (5 randomized and 73 retrospective). RPD was associated with lower blood loss compared to OPD (mean difference [MD], –163.85 mL) and LPD (MD, –84.14 mL). Hospital stays were also shorter for RPD compared to OPD (MD, –2.50 days) and LPD (MD, –1.88 days). In contrast, OPD was the most time-efficient approach compared to LPD (MD, –77.61 minutes) and RPD (MD, –73.30 minutes). Mortality rates, severe complications, clinically relevant postoperative pancreatic fistula rates, and reoperation rates were comparable across all surgical approaches. In terms of oncologic safety, lymph node yield and R0 resection rates were similar for all modalities. Conclusions While OPD is the most time-efficient approach, RPD provides significant advantages in reducing intraoperative blood loss and shortening hospital stays compared to both LPD and OPD.

Background: Transthyretin amyloidosis, a protein-misfolding disorder characterized by systemic amyloid deposition, can be classified as wild-type transthyretin amyloidosis (ATTRwt) or hereditary transthyretin amyloidosis (ATTRv), depending on the presence of transthyretin (TTR) gene variants. We examined the genetic distribution of TTR variants in Korean patients diagnosed with ATTRv. Methods: We retrospectively reviewed 801 participants who underwent TTR analysis at Samsung Medical Center from 2012 to 2024. The participants were categorized into two groups: in-house probands or relatives, and externally referred probands or relatives. Results: Pathogenic or likely pathogenic TTR variants were detected in 36 of 165 in-house probands (21.8%), among which D38A was the most frequent variant (50.0%; 18/36), followed by M13dup and E89K (8.3% each). Among referred probands, D38A was predominant (54.5%; 12/22), followed by M13dup (22.7%; 5/22). Cardiac amyloid involvement was the most common manifestation, observed in 97.2% (35/36) of in-house probands with ATTRv, followed by peripheral nervous system (PNS; 94.4%) and autonomic nervous system (ANS; 88.9%) involvement. In contrast, ANS involvement was most prevalent among in-house relatives who underwent organ evaluation (61.5%; 24/39), followed by cardiac (52.1%; 25/48) and PNS (48.7%; 19/39) involvement. Five of the eight in-house relatives harboring M13dup (62.5%) showed organ involvement, primarily in the ANS, supporting the pathogenicity of this variant. Conclusions This study provides the largest single-institution dataset of Korean patients with ATTRv, incorporating systematic organ assessments. The predominance of the unique TTR variants D38A and M13dup delineates a distinct genetic landscape that may facilitate accurate and timely diagnosis of ATTRv in the Korean population.

Myopia, particularly high myopia, is a significant risk factor for several ocular pathologies including cataract, glaucoma, and retinal detachment. Excessive axial elongation associated with high myopia can induce biomechanical stretching, increasing the risk of serious complications like posterior staphyloma and myopic maculopathy. Global meta-analyses estimate that approximately 10 million people were visually impaired due to myopic maculopathy in 2015, with 3 million being blind. Recent nationwide surveys in South Korea revealed a prevalence of 65.4% for myopia and 6.9% for high myopia in children and adolescents, highlighting the urgent need for effective management. Delaying the onset and slowing the progression of myopia during childhood and adolescence is crucial for reducing the potential lifetime risk of these complications. This consensus statement, prepared by the Korean Myopia Society for the Korean Association for Pediatric Ophthalmology and Strabismus (KAPOS), reviews the current evidence for myopia control interventions and provides management strategies applicable to the South Korean clinical setting. Key interventions covered include lifestyle modifications (outdoor time, near work adjustment), optical methods (myopia-control spectacle lenses, dual-focus soft contact lenses, orthokeratology), and pharmacologic treatment (low-concentration atropine), as well as combination therapies. The statement also addresses patient selection, treatment outcome evaluation using spherical equivalent and axial length changes, and the crucial aspects related to treatment cessation and the rebound effect.

Objective: This study aimed to evaluate the feasibility, safety, and oncologic outcomes of irreversible electroporation (IRE) using a clustered electrode in patients with locally advanced pancreatic cancer (LAPC). Materials and Methods: In this single-center prospective cohort study, 13 patients with LAPC (median age, 60 years; range, 48–78 years) underwent clustered electrode IRE between September 2022 and September 2024. Patient characteristics, procedural details, and clinical outcomes were recorded. Endpoints included technical success, procedure-related complications, overall survival (OS), and progression-free survival (PFS). Results: Tumors were located in the pancreatic head in four patients (30.8%) and in the body/tail in nine (69.2%). The median tumor size was 2.4 cm (1.5–4.0 cm), and vascular invasion was present in all patients. Technical success was achieved in all patients. Intraoperative IRE was performed in 11 (84.6%) patients, and 2 (15.4%) patients underwent percutaneous IRE. Gastrointestinal bleeding events as major complications occurred in two patients (15.4%) and, both were successfully controlled by embolization. No 60-day mortality was observed. At a median follow-up of 24.5 months (range, 9.9–33.4 months) after IRE, median OS and PFS from IRE were 20.1 and 14.5 months, respectively. Conclusion IRE using clustered electrodes for LAPC appears to be a feasible therapeutic approach, offering reliable technical success and acceptable safety. Survival outcomes are encouraging; however, larger, controlled studies are required.

Objective: This study aimed to compare the therapeutic outcomes of no-touch (NT) radiofrequency ablation (RFA) vs. tumorpuncture microwave ablation (MWA) in the treatment of single hepatocellular carcinomas (HCCs) measuring ≤3 cm. Materials and Methods: This multicenter retrospective study included 304 patients who underwent either NT-RFA (n = 144) or MWA (n = 160) for a single HCC measuring ≤3 cm. Comparative analyses were conducted for the overall cohort, while 81 patients per group were matched using propensity score matching (PSM). The analyzed outcomes included technical success, primary technique efficacy, local tumor progression (LTP), and major complications. Cumulative LTP was estimated using Kaplan–Meier analysis and compared using the log-rank text, while the rate of ablative margin ≥5 mm and ablation time were compared using Chi-squared and Mann–Whitney U tests, respectively. Results: Technical success was achieved in 98.6% (142/144) and 100% (160/160) of in the NT-RFA and MWA patients, respectively before PSM (P = 0.224), and 98.8% (80/81) and 100% (81/81) after PSM (P = 1.000). The primary technique efficacies were 98.6% (142/144) and 100% (160/160) before PSM (P = 0.224), and 97.5 % (79/81) and 100% (81/81) after PSM (P = 0.497), respectively. The 1-, 2-, and 3-year cumulative LTP rates were 1.4%, 1.4%, and 2.3%, respectively, for NTRFA and 5.1%, 8.6%, and 8.6%, respectively, for MWA before PSM (P = 0.013). After PSM, the corresponding rates were 0%, 0%, and 0% for NT-RFA, and 7.6%, 10.4%, and 10.4% for MWA (P = 0.006). Major complications were not observed. NT-RFA achieved a higher proportion, with an ablative margin ≥5 mm (88.7% [126/142] vs. 71.9% [115/160]; P < 0.001), but required longer ablation times (median, 10.0 vs. 6.0 min; P < 0.001). Conclusion NT-RFA showed superior local tumor control compared to MWA, despite greater procedural complexity and longer ablation times.

Background: In the era of nucleoside analogs (NA), we investigated the safety of using hepatitis B surface antigen (HBsAg)-positive grafts in liver transplantation (LT) using nationwide KOTRY data. Methods: Among 4,265 adult LTs in the KOTRY registry (April 2014–January 2020), 20 (0.5%) used HBsAg(+) grafts. The S(+) group was compared with HBsAg-nega-tive groups, both HBcAb(+) (C[+]) and HBcAb(−) (SC[−]), using 1:1 propensity scorematching. Patient and graft survival were evaluated using Kaplan–Meier analysis.Cox regression was used to identify prognostic factors. Results: No significant differences were observed in patient or graft survival be-tween S(+) and C(+) or SC(−) groups. Key prognostic factors for patient survivalincluded age, HCC, MELD score, ascites, and encephalopathy. For graft survival, HCC, preoperative HCC treatment, MELD score, ascites, and encephalopathy were significant. HBV recurrence occurred in the S(+) group, but did not compromise outcomes. Conclusion In HBV-endemic regions, HBsAg(+) liver grafts can be safely used to expand the donor pool without compromising LT outcomes when combined with appropriate prophylaxis.

Background: Warm ischemia is a major contributor to ischemic cholangiopathy and non-anastomotic biliary strictures (NAS) after liver transplantation, particularly in donation-after-circulatory-death grafts. However, the isolated impact of warm ischemia on peribiliary fibrosis is difficult to delineate because clinical settings involve overlapping effects of cold ischemia, reperfusion injury, and alloimmunity. This study aimed to establish a non-transplant rat model that isolates warm ischemic biliary injury and to compare the antifibrotic effects of rapamycin and tacrolimus. Methods: Warm ischemia was induced in Sprague–Dawley rats by ligating both ends of the peribiliary vascular plexus and the hepatic artery, followed by 30 minutes of portal vein clamping. Rats were randomly assigned to control, tacrolimus (1 mg/kg/day), or rapamycin (1 mg/kg/day) groups (n=15 per group). Serum alanine aminotransferase, alkaline phosphatase, gamma-glutamyl transferase, and total bilirubin were measured serially. Hematoxylin and eosin (H&E) and Sirius red staining were performed at 1, 3, and 6 weeks. Peribiliary fibrosis was quantified using digital image analysis of collagen area fraction. Results: Warm ischemia induced acute hepatobiliary injury with transient enzyme elevations, but no significant intergroup differences were observed. Histologically, biliary epithelial proliferation and collagen deposition increased progressively and became prominent at 6 weeks. At this time point, fibrosis ratios differed significantly (overall p=0.002): controls showed the highest fibrosis (4.8%), followed by tacrolimus (2.4%) and rapamycin (1.7%). Both immunosuppressants significantly reduced fibrosis compared with controls (p<0.05), whereas the difference between tacrolimus and rapamycin was not significant. Conclusion This warm ischemia model demonstrates that isolated ischemic injury alone can induce progressive peribiliary fibrosis. Rapamycin and tacrolimus attenuated fibrosis, with rapamycin producing the lowest collagen deposition. These findings provide mechanistic insight into ischemic cholangiopathy after liver transplantation—particularly in donation after circulatory death grafts—and underscore the need for further studies using models that incorporate cold ischemia, reperfusion, and alloimmune factors.

Purpose: Weight reduction (WR) can reduce liver volume, affecting the graft-to-recipient weight ratio (GRWR). This study aimed to evaluate the decrease in liver volume after WR and analyze risk factors affecting liver volume reduction in potential liver donors with steatosis. Methods: We retrospectively reviewed data of 147 potential liver donors with steatosis who participated in a WR program prior to liver transplantation between January 2016 and December 2021. Total liver volume (TLV) was measured using CT and MRI. Risk factors for large liver volume reduction (≥10%) were analyzed using multivariate logistic regression. Results: Ninety-seven donors (66.0%) underwent donor hepatectomy after WR. Liver volumes showed a statistically significant decrease (from 1,399.6 ± 315.4 mL to 1,283.6 ± 271.2 mL, P < 0.05). Thirty-eight donors (42.7%) showed large liver volume reduction. There was a more significant reduction in weight, AST, and ALT in the large liver volume reduction group than in the small liver volume reduction group (all P < 0.05). WR percentage and ALT abnormalities were independent risk factors for large liver volume reduction (odds ratio, 1.184 [95% confidence interval, 1.054–1.329] and odds ratio, 5.502 [95% confidence interval, 1.660–18.229], respectively; all P < 0.05). Conclusion Potential liver donors with 7% or more WR or ALT abnormality require liver volume/GRWR remeasurement after WR to ensure adequate graft size and prevent small-for-size syndrome.

Purpose: Right lobe living donor liver transplantation (LDLT) with dual portal veins (PVs) remains technically challenging.This study aimed to identify independent risk factors for PV complications. Methods: We retrospectively analyzed 111 recipients of dual PV LDLT between 2011 and 2020. Recipient characteristics, anatomical geometry, and surgical factors were evaluated. Outcomes were overall PV complications and major PV complications (Clavien-Dindo grade ≥III). Logistic regression was performed. Results: PV complications developed in 41 patients (36.9%), including 16 major events (14.4%). Univariate analysis revealed associations with right posterior PV (RPPV) diameter, axial angle, and coronal angle. On multivariate analysis, larger RPPV diameter (odds ratio [OR], 1.79; P = 0.041) and wider axial angle (OR, 1.08; P = 0.015) were independent predictors of major PV complications. Reconstruction method was not significant. Patients with overall major Clavien-Dindo grade ≥IIIcomplications had inferior 100-month survival (80% vs. 100%; P = 0.014, log-rank test). Conclusion In dual PV LDLT, anatomical geometry—specifically RPPV diameter and axial angle—independently predicts major PV complications, whereas surgical technique does not. Preoperative 3-dimensional imaging and anatomical risk stratification should inform donor selection and surgical planning.